In recent years, various systems are known as systems for changing a situation of a user. For example, there is disclosed a technology in which an intermediary that mediates between a user and an answerer provides a question of the user to a plurality of answerers, selects an appropriate answer proposal from among answer proposals obtained from the plurality of respective answerers, and makes an answer to the user on the basis of the selected answer proposal (e.g. refer to Patent Literature 1).
In addition, there is disclosed a technology in which an intermediate center searches answers pre-registered in a database, on the basis of a question of a user, and generates an answerer list on the basis of the question of the user in a case where an answer is not obtained from the database (e.g. refer to Patent Literature 2). In this technology, an answerer with a higher degree of matching to the question of the user is positioned at a higher place in the answerer list, and answerers receive the question of the user in order from the answerer positioned at the higher place in the answerer list.